This invention relates to a unfilled single loose tube fiber optic cable in which no filling or flooding compounds are used; yet, the optical fibers are protected from penetrating water by a unique positioning of water absorbing yarn or tape.
Most fiber optic cable of the loose tube variety employ a filling material inside of the buffer tube and flooding material between the buffer tube and a jacket which circumscribes the buffer tube. The purpose of the flooding and filling compounds is to shield the optical fibers from water. Such is a "wet" construction because both the flooding and filling material have respective viscosities that can and do wet a given surface. A water impervious unfilled loose tube fiber optic cable is desirable because the fibers are more easily accessible and more environmental acceptable because the filling and flooding compounds would be eliminated. Yet, the optical fibers within the buffer tube would be protected against water. Worldwide there is a growing need to recycle plastic and other materials. Plastic cables containing flooding or filling compounds are not subject to recycling because of the flooding and filling compounds. Existing landfills are beginning to object to anything that has flooding or filling compounds, thus the desirability of a unfilled cable which would be recyclable and/or non objectionable for landfill disposal. It is towards the solution to this problem the present invention is directed.